Project description:Maintenance and self-renewal of the spermatogonial stem cell (SSC) population is the cornerstone of male fertility. In this manuscript we have identified a key role for the nucleosome remodelling protein Chromodomain Helicase DNA binding protein 4 (CHD4) in regulating SSC function. Gene expression analyses revealed that CHD4 expression is largely restricted to spermatogonia in the mouse testis, and is particularly enriched in SSCs. Using spermatogonial transplantation techniques and RNAi mediated knockdown it was established that loss of Chd4 expression significantly impairs SSC regenerative capacity, resulting in a ~50% reduction in colonisation of recipient testes. A single cell RNA-seq comparison depicted reduced expression of ‘self-renewal’ genes such as Gfra1 and Pten following Chd4 knockdown, along with increased expression of signature progenitor genes, Neurog3 and Dazl. Co-immunoprecipitation analyses demonstrated that CHD4 regulates gene expression in spermatogonia not only though its traditional association with the remodelling complex NuRD, but also via interaction with the GDNF-responsive transcription factor SALL4. Cumulatively, the results of this study depict a previously unappreciated fundamental role for CHD4 in controlling fate decisions in the spermatogonial pool.
Project description:To understand the role of the nucleosome remodelling protein CHD4 in regulating spermatogonial stem cell function, we performed single cell RNA-sequencing on undifferentiated spermatogonia from primary culture that had been transfected with either control (non-targeting) siRNA or Chd4 siRNA. Transcriptome profiling revealed reduced expression of ‘self-renewal’ genes following Chd4 knockdown, along with increased expression of signature progenitor genes. Overall, CHD4 was demonstrated to primarily act as an activator of gene expression in SSCs. In pairing these data with additional analyses, including use of an Id4-eGfp transgenic mouse line, spermatogonial transplantation, and co-immunoprecipitation experiments: the findings of our study demonstrated a previously unappreciated and fundamental role for CHD4 in controlling fate decisions in the spermatogonial pool.
Project description:Maintenance and self-renewal of the spermatogonial stem cell (SSC) population is the cornerstone of male fertility. Here, we have identified a key role for the nucleosome remodeling protein CHD4 in regulating SSC function. Gene expression analyses revealed that CHD4 expression is highly enriched in the SSC population in the mouse testis. Using spermatogonial transplantation techniques it was established that loss of Chd4 expression significantly impairs SSC regenerative capacity, causing a ∼50% reduction in colonization of recipient testes. An scRNA-seq comparison revealed reduced expression of "self-renewal" genes following Chd4 knockdown, along with increased expression of signature progenitor genes. Co-immunoprecipitation analyses demonstrated that CHD4 regulates gene expression in spermatogonia not only through its traditional association with the remodeling complex NuRD, but also via interaction with the GDNF-responsive transcription factor SALL4. Cumulatively, the results of this study depict a previously unappreciated role for CHD4 in controlling fate decisions in the spermatogonial pool.
Project description:Male spermatogenesis is sustained by homeostatic balance between the self-renewal and differentiation of spermatogonial stem cells (SSCs), which is dependent on the strict regulation of transcriptional factor and chromatin modulator gene expression. Chromodomain helicase DNA-binding protein 4 (CHD4) is highly expressed in SSCs but roles in mouse spermatogenesis are unexplored. Here, we report that the germ-cell-specific deletion of Chd4 resulted in complete infertility in male mice, with rapid loss of SSCs and excessive germ cell apoptosis. Chd4-knockdown in cultured SSCs also promoted the expression of apoptosis-related genes and thereby activated the tumor necrosis factor signaling pathway. Mechanistically, CHD4 occupies the genomic regulatory region of key apoptosis-related genes including Jun and Nfkb1. Together, our findings reveal the determinant role of CHD4 in SSCs survival in vivo, which will offer insight into the pathogenesis of male sterility and potential novel therapeutic targets.
Project description:Male spermatogenesis is sustained by homeostatic balance between the self-renewal and differentiation of spermatogonial stem cells (SSCs), which is dependent on the strict regulation of transcriptional factor and chromatin modulator gene expression. Chromodomain helicase DNA-binding protein 4 (CHD4) is highly expressed in SSCs but roles in mouse spermatogenesis are unexplored. Here, we report that the germ-cell-specific deletion of Chd4 resulted in complete infertility in male mice, with rapid loss of SSCs and excessive germ cell apoptosis. Chd4-knockdown in cultured SSCs also promoted the expression of apoptosis-related genes and thereby activated the tumor necrosis factor signaling pathway. Mechanistically, CHD4 occupies the genomic regulatory region of key apoptosis-related genes including Jun and Nfkb1. Together, our findings reveal the determinant role of CHD4 in SSCs survival in vivo, which will offer insight into the pathogenesis of male sterility and potential novel therapeutic targets.
Project description:To understand the functional role of CHD4, a member of the Nucleosome Remodeling and Deacetylase (NuRD) complex, in establishing chromatin states in the formation and maintenance of ovarian reserve and the maintenance of female and male germ cells, we eliminated CHD4 function in germ cells using Ddx4-Cre and Gdf9-iCre to generate CHD4 conditional knockout (Chd4 DcKO and GcKO) mice. We discover that CHD4 defines the chromatin state that ensures germ cell survival, thereby enabling the long-term maintenance of female and male germ cells. We then performed ATAC-seq in Chd4 Dctrl and Chd4 DcKO non-growing oocytes and undifferentiated spermatogonia.
Project description:To understand the functional role of CHD4, a member of the Nucleosome Remodeling and Deacetylase (NuRD) complex, in establishing chromatin states in the formation and maintenance of ovarian reserve and the maintenance of female and male germ cells, we eliminated CHD4 function in germ cells using Ddx4-Cre and Gdf9-iCre to generate CHD4 conditional knockout (Chd4 DcKO and GcKO) mice. We discover that CHD4 defines the chromatin state that ensures germ cell survival, thereby enabling the long-term maintenance of female and male germ cells. We then performed CUT&Tag for CHD4 in Chd4 f/f P1 oocytes.
Project description:To understand the functional role of CHD4, a member of the Nucleosome Remodeling and Deacetylase (NuRD) complex, in establishing chromatin states in the formation and maintenance of ovarian reserve and the maintenance of female and male germ cells, we eliminated CHD4 function in germ cells using Ddx4-Cre and Gdf9-iCre to generate CHD4 conditional knockout (Chd4 DcKO and GcKO) mice. We discover that CHD4 defines the chromatin state that ensures germ cell survival, thereby enabling the long-term maintenance of female and male germ cells. We then performed gene expression profiling analysis using data obtained from RNA-seq of Chd4 Dctrl and Chd4 DcKO non-growing oocytes and undifferentiated spermatogonia, and Chd4 Gctrl and Chd4 GcKO non-growing and growing oocytes.
Project description:The foundation of spermatogenesis and lifelong fertility is provided by spermatogonial stem cells (SSCs). SSCs divide asymmetrically to either replenish their numbers (self-renewal) or produce undifferentiated progenitors that proliferate before committing to differentiation. However, regulatory mechanisms governing SSC maintenance are poorly understood. Here, we show that the CCR4-NOT mRNA deadenylase complex subunit CNOT3 plays a critical role in sustaining spermatogonial populations in mice. We found that Cnot3 is highly expressed in undifferentiated spermatogonia, and its deletion in spermatogonia resulted in germ cell loss and infertility. Furthermore, it is required for SSC self-renewal based on single cell analyses in vivo and SSC culture in vitro. Mechanistically, Cnot3 deletion led to the de-repression of transcripts encoding factors involved in spermatogonial differentiation, including those in the glutathione redox pathway that are critical for SSC maintenance. Together, our study reveals that CNOT3 – likely via the CCR4-NOT complex – actively degrades transcripts encoding differentiation factors to support the spermatogonial pool and ensure the progression of spermatogenesis, highlighting the importance of CCR4-NOT-mediated post-transcriptional gene regulation during male germ cell development.
Project description:The foundation of spermatogenesis and lifelong fertility is provided by spermatogonial stem cells (SSCs). SSCs divide asymmetrically to either replenish their numbers (self-renewal) or produce undifferentiated progenitors that proliferate before committing to differentiation. However, regulatory mechanisms governing SSC maintenance are poorly understood. Here, we show that the CCR4-NOT mRNA deadenylase complex subunit CNOT3 plays a critical role in sustaining spermatogonial populations in mice. We found that Cnot3 is highly expressed in undifferentiated spermatogonia, and its deletion in spermatogonia resulted in germ cell loss and infertility. Furthermore, it is required for SSC self-renewal based on single cell analyses in vivo and SSC culture in vitro. Mechanistically, Cnot3 deletion led to the de-repression of transcripts encoding factors involved in spermatogonial differentiation, including those in the glutathione redox pathway that are critical for SSC maintenance. Together, our study reveals that CNOT3 – likely via the CCR4-NOT complex – actively degrades transcripts encoding differentiation factors to support the spermatogonial pool and ensure the progression of spermatogenesis, highlighting the importance of CCR4-NOT-mediated post-transcriptional gene regulation during male germ cell development.